The combined value of stocks owned by South Korea's 100 richest stockholders has jumped 21.3 percent, helped by a rally in the stock market, industry data showed Thursday.

The benchmark Korea Composite Stock Price Index gained 16.3 percent to 2,357.53 on Wednesday, compared with a closing price of 2,026.16 as of Jan. 2 this year.

According to the data by industry tracker Chaebul.com, the value of stocks owned by the 100 richest stockholders stood at 113.2 trillion won ($99.1 billion), up from 93.1 trillion won as of Jan. 2. 

Lee Kun-hee, chief of the Samsung Group and Chairman of Samsung Electronics, saw his stock value jump 21.3 percent to 17.3 trillion won. He has been hospitalized since May 2014 after suffering from a heart attack.

Lee Jae-yong, the only son of the Samsung chief and vice chairman of Samsung Electronics Co., also saw his stock value rise by 12.9 percent to 7.5 percent.

Shares of Samsung Electronics climbed 31.5 percent as of Wednesday, compared with the first trading day of this year.

Bang Jun-hyuk, founder and chairman of the board of Netmarble Games, became a new billionaire after the mobile-game firm debuted its stocks.

Bang holds a 24.47 percent stake worth 3.2 trillion won in Netmarble.

Hyundai Motor Group Chairman Chung Mong-koo, however, saw his stock value fall by 0.8 percent to 4.83 trillion won, according to the data. (Yonhap)